Gas lift for oil wells



Jan. 20, 1931. w A. GAMMACK ET AL 1,739,866

(ms LIFT FOR OIL WELLS Filed April 18; 1921' 2 Sheets-She et 1 J'f/VEQ T FZ M44 49/7 Ii 67 7406 (fr er/ME 1931. w. A. GAM MACK ET AL 1,789,866

GAS L'IFT FOR OIL WELLS Filed April 18, 192'. 2 Sheets Sheet 2 Patented Jan. 20, 1931 UNITED STATES PATENT oFFlcE WILLIAM A. GAMMAOK AND DONALD G. KNOX, 0F LONG BEACH, CALIFORNIA, AS-

SIGNORS, BY MESNE ASSIGNMENTS TO JORDAN & TAYLOR, INC., 0] LOS ANGELES, CALIFORNIA, A CORPORATION OF CALIFORNIA Gas 1.1m: roa on. waits Application ma April 18,

Our invention relates .to well pumps and particularly a pump in which the liquid is lifted to the surface of the ground by gas.

The ordinary gas-lift consists of a liquid delivery tube which is extended from the surface of the ground to a point below the liquid level. A pipe or equivalent is provided for delivering gas under pressure to the lower end-of the liquid delivery tube. The gas passes upward through this delivery tube and carries the liquid therewith.

It is very undesirable to place a back-pres-- sure on the oil bearing sands ofan 'oil well for the reason that it tends to diminish the yield of the well. 4

One of the objects of our invention is to provide a gas-lift in which no back-pressure will be placed on the bearing formation.

An'other'object of the invention is to provide a gas-lift in which there will be no back-flow of liquid from the gas-lift into the bearing formation. I

In wells where the yield is small we find it more economical to pump intermittently.

It is one of the objects of this'invention to provide a gas-lift which is adapted to operate either continuously or intermittently.

A still further object of the invention is to provide a gas-lift in which the natural gas of the well assists in raisi g the liquid to the surface of the ound.

Other objects and advantages of the invention will be made apparent in the following description. Our invention may be best understood by referring to the drawings in which a pre-' ferred form is illustrated Referring to the drawings: I Fi 1 is a-vertical section showing the gas-11ft installed in a well.

' Fi 2 is an enlarged vertical section showing t e gas-lift, per se.

Fig. 3 is a cross section taken on the line, 3-3 of Fig. 2.

Fig. 4 is a cross sectlon taken on the line 4-4 of Fig. 2..

Fig. 5 is a cross section taken on the line 5-v- 5 of Fig. 2. i

Fig. 6 is a cross section taken on the line 6-6 ofFig. 2.

1927. Serial no. 184,492.

The form of the invention shown in the drawings is adapted to be installed in a well upper end of which is provided with a casing head 13. The liquid level. of the well is indicated at A-A in Fig. 1, ,Extended downward from the upper end of the-well casing 12 is a delivery pipe 15. The upper end of the delivery pipe 15 above the casing head 13 is provided with an elbow 16 to which a pipe'17 is joined, this pipe 17 extending to a suitable storage or place of utility for the liquid. Attached to the lower end of the delivery pipe 15 is the gas-lift of our invention per se, this gas-lift being indicated. as a whole, b thenumeral 18.

Referring particular y to Fig. 2,' secured to the lower end of the delivery pipe 15 is a coupling 20. This coupling 20 has a pressure-gas member 21 connected thereto which extends downward therefrom. The lower end ofthe pressure-gas member 21 extends a great distance below the liquid level of the well. The submergence of the lower end of" this pressune-gas member may be 500 to 1000 feet. 'At the extreme lower end thereof is a main valve which is in the form of acon'ical seat 22 and a ball 23. The purpose of this main valve is to permit a flow of liquid into the lower end of the pressure-gas member 21 but to prevent a flow of the liquid from the pressure-gas m'ember ina reverse direction;

A supporting pin 24 extends diametrall across the pressure-gas member 21 imme-' diately above the main valve. Supported by thls supportlng pin 24 and extending upwardin achamber 25 defined inside the mem-' ber 21 above the main valve is a delivery tube 26. The delivery'tube 26 is of a substantially smaller diameter thanthepressure-gas member 21 and extends upward through the chamber 25'to a point above the coupling 20. Near the upper end of the pressure-gas member 21 and between it and the delivery tube 26 is a packer 27 defining the upper end, of the chamber 25. The packer 27 consists of a lower ring 28 which islowered into the annular space between the two parts in consideration and is supported by a split ring 29 which rests in an internal groove of the pressure-gas member 21. A rubber packer 30 is placed above the lower ring 28, and screwed onto the delivery tube 26 is an upper ring 32 which compresses the packing so as to provide a tight seal at this point between the delivery tube 26 and the pressure-gas member 21. The closing of the upper end of this space between the pressure-gas member 21 and the delivery tube 26 forms a pressuregas passage 34. By an inspection of the lower part of Fig. 2 it will be seen that this pressure-gas passage 34 is in communication with the interior of the delivery tube 26 by way of the lower end of it.

Surrounding the pressure-gas member 21 just below the coupling 20 is an outer member in the form of a shell 35. The shell 35' forms an annular space around the'pressuregas member 21, which space serves as a wellgas exhaust passage 36. The shell 35 is secured to the pressure-gas member 21 at the lower end thereof by a series of spaced spotwelds 37 and also by a means shown clearly in Fig. 4. The pressure-gas member 21 and the shell 35 are drilled with aligning holes 38 and 39. The two parts are then welded together, the holes being filled with welding material as indicated at 40. This means rigidly secures these two parts together. A seal at the upper end of the shell 35 is provided by engagement of the lower end of the coupling 20 with the upper end of the shell. The contacting surfaces may be ground so that a good joint will result.

The lower end of the shell 35 is provided with a packer 42. This packer 42 is held in place on the shell 35 by a special collar 43 which is screwed onto the lower end thereof. The packer is so designed that it will engage the well casing 12 and provide a seal between the well casing 12 and the shell 35. The space in the well casing 12 around the gaslift 18 and the delivery pipe 15 is thus converted into a. pressure-gas chamber 44. this under pressure is supplied to this pressuregas chamber 44 by means of a pressure-prim 45 connected to the casing head 13 by a pipe 46.

The pressure-gas chamber 44 is connected to the pressure-gas passage 34 by pressureretaining valves 47 which are illustrated in detail in Fig. 4. The weldedbosses 40 which are used to attach the pressure-gas member 21 and the shell 35.together are drilled with radial openings 48. The pressure-relief valves each have a passage '49 provided therethrough, which passage provides a seat against which a ball 50 is resiliently held by means of a compression spring 51. These parts are installed in the passage 49 through the inner ends of the valves 47 and are retamed therein by an apertured plug 53. The

purpose of the pressure-retaining valves 47 is toprevent any passage of pressure-gas from the pressure-gas chamber 44 into the pressure-gas passage 34 unless a predetermined pressure is exceeded. I prefer to have the minimum pressure at which gas willpass through these valves 47 to be 100 pounds. Usually we employ greater pressure, but 1n some cases less pressure may be used. The valves 47 are thus pressure-operated by increasing the pressure supplied to the upper end of the pressure-gas chamber 44.

Returning our attention to. Fig. 2, it will be seen that the packer 42 is placed slightly above the liquid level A-A of the well. It will further be seen that the well-gas exhaust passage 36 is at its lower end connected to the interior of the well. The upper end of the well-gas exhaust passage 36'is communicated with the interior of the delivery pipe 15 by means of d'ucts provided in the upper end of the pressure-gas member 21. A check valve is provided at the upper end of the well-gas exhaust passage 36 to prevent a reverse flow from the interior of the delivery pipe 15 into the interior of the well below the packer 42. This check valve consists of a ring-valve member 56 which rests in an annular channel 57 which is formed around the ducts 55. By gravity the ring-valve member 57 seats at faces provided at the upper end of the well-gas exhaust passage 36 and closes it. Stop pins 58 extend downward in the chamber 57 from the coupling 20 and prevent the ring-valve. member 56 from risin too great a distance from its seat or from being twisted so that it will not properly seat. Gas passing upward through the well-gas exhaust passage lifts'the ring-valve member 56 from its seat, which permits it to pass through the chamber 57 and the ducts 55 into the interior of the delivery pipe 15.

We have in the foregoing description pointed out the essential parts of the invention.

p gas chamber We shall consider that the gas-lift is being set into operation after a i period of rest. The gas-lift will, therefore be filled with a liquid up to the level i l-11 of the well. This is done by force of gravity, the main valve opening to permit an ingross of liquid. lVhen the ingressof liquid ceases, the main valve will seat by gravity, closing the lower end of the pressure-gas member 21. \Vhen the pressure of the pres sure-gas in the prcssure-gas chamber 44 exceeds that in the passage 34 by 100 pounds (this being the setting of the pressure-retaining valves 47), there will be a flow from the pressure-gas chamber 44 into the pressuregas passage 34. .This gas flows downward through the passage and displaces the liquid the lower end of the delivery tube. The main 'If the gas wells having high-pressurev formations, the

valve being closed at this time prevents any of the liquid from backing into the inter1or of the well and therefore revents a backpressure being placed on the ormation. The

pressure-gas upon reaching the 'lower end of the delivery tube 26 flows upward therethrough and forces the oil in the delivery tube u ward into the delivery ipe in which it is conducted to the sur ace of the ground. We wish to make it quite clear that any excess of pressure at the lower end of the pressure-gas member 21 securely retains the main valve closed. This is true when the gas-' lift is being used on low-pressure formations. ift, on the other hand, is used in pressure of the formation may be greater than the gas-pressure employed. In such cases the pressure in the well will be -greater than the pressure inthe pressure-gas member 21 and even though there is a flow of pressure-gas therethrough, there will also be an ingress of liquid from the lower end thereof. In such a case there will be no back-pressure placed on the formation because the pressure delivery pressure.

of the pressure-gas is not suflicient to cause it. Any well-gas which may accumulate in the interior of the well passes upward around the pressure-gas member 21 to the space above the oil level A-A and below the packer 42. This well-gas is free to pass upward through the well-gas exhaust passage 36 and if it is of sufficient pressure will open the ring-valve member 56 and flow into the interior of the assist in elevating it to the surface of the ground.

On wells of low formation-pressure and where the yield of liquid is quite small, the gas-lift cannot be economically operated over a long period of time. This is true where the pressure of the pressure-gas in order to elevate the liquid to the surface of the ground must be greatly in excess of the formation- In such wells it'is advantageous to operate the gas-lift intermittently. When the flow of pressure-gas is arrested, the pressure in the delivery tube and pressure-gas member is reduced to less than the pressure in the interior of the well. The main valve will open and liquid will flow into the lower end of the chamber of the pressureas member 21 and into the delivery tube 26, lling them to the level of the well. After a short period of time which is sufiipient to allow this ingress to take place, the pressuregas is a ain'made to flow and the same operation o lifting the liquid, as previously explained, is repeated.

From the foregoing description it should ber of respects.

, pipe 15. This well-gas will intermingle'with the liquid being raised and will is an important advance in the art in a num- First, there is absolutely no back-pressure on the liquid-bearing formations or no back-flow of liquid thereinto. In the second place, the gas-lift is especially suitable for intermittent operation and on low-pressure formations is found to be very economical. In the-third place, the well-gas is utilized to assist theqvressure-gas in lifting the liquid to the surface of the ground. This is quite important because it conduces to economy and also because it serves as an exhaust means for the well-gas which prevents an accumulation of it, and consequently a back-pressure which would under, ordinary circumstances lower the level A-A of the liquid in the well 11.

The apparatus illustrated in the drawings and described heretofore is a preferred form,

but obviously is not the only form in which the invention may be embodied. The gas-lift is made entirely of pipes, which is found to be economical. The novel parts of the invention are briefly enumerated as follows First, it is necessary to have a liquid delivery means through which liquid is delivered to the surface of the ground. In the form of the invention illustrated this liquid delivery means is in the form of the delivery pipe 15 and the delivery tube 26. The main valve at the lower end of the pressure-gas member is also important, although notessential when pumping continuously rather than intermit tently. It is also essential to have a pressuregas supply means. This pressure-gas supply means in .the drawings is provided by the pump 45, the ipe 46, and the pressure-gas chamber 44. Knother important part is the Well-gas conveying means which conveys the well-gas from the interior of the well to the interior of the delivery pipe 15. In addition to this, the pressure-retaining valves 47 and the check valve at the upper end of the wellgas exhaust passage are important. From this brief explanation of the essential parts it should be very evident that any design which provides any of these parts in various combinations comes within the scope of this invention. 7

We claim as our invention:

1. A gas-lift comprising: a liquid delivery means adapted to be extended into a well, the lower end extending below the liquid level of said well; a main valve near the lower end of said liquid delivery means for preventing liquid from flowing from said liquid delivery means into said well; pressure-gas supply means forsupplying pressure-gas to the lower end'of said liquid delivery means; and wellgas conveying means for conveying well-gas from the said liqui delivery means at a point above the li uid level of said well.

2. gas-lift comprising: a liquid delivery means adapted to be extended into a well, the

(sipace in said well to the interior of lower end extending below the liquid level of said well; a main valve near the lower end of said liquid delivery means for preventing liquid from flowing from said liquid delivery -means into said well; pressure-gas supply means for supplying pressure-gas to the lower end of said liquid delivery means; well-gas conveying means for conveying well-gas from the space in said well to the interior of said liquid delivery means at a point above the liquid level of said well; and a well-gas check valve for preventing a reverse flow through said well-gas conveymg means.

3. A gas-lift comprising: a liquid delivery means adapted to be extended into a well, the

lowerend extending below the liquid levelpressure-gas chamber around said liquid delivery means; a pressure-gas member for supplying pressure-gas from said pressuregas chamber to the lower end of said liquid delivery means; and Well-gas conveying means for conveying well-gas from the space 'in said well to the interior of said liquid delivery means at a point above the liquid level of said well.*

4. A gas-lift comprising: a liquid delivery means adapted to be extended into a well, the lower end extending below the liquid level of said well a main valve near the lower end of said liquid delivery means for preventing liquid from flowing from said liquid delivery means into said well; a packer surrounding said liquid delivery means near the liquid level of said well, said packer providing a pressure-gas chamber around said liquid delivery means; a pressure-gas member for supplying pressure-gas from said pressuregas chamber to the lower end of said liquid delivery means; well-gas conveying means for conveying well-gas from the space in said well to the interior of said liquid delivery means at a point above the liquid level of said well; and a well-gas check valve for'preventing a reverse flow through said well-gas conveying means.

5. A gas-lift comprising: a liquid delivery means adapted to be extended into a well, the lower end extending below the liquid level of said well; a main valve near the lower end of said liquid delivery means for preventing liquid from flowing from saidliquid delivery means into said well; a packer surrounding said liquid delivery means near the liquid level of said well, said packer providing a pressure-gas chamber around said liquid delivery means; a pressure-gas member surrounding said liquid delivery means for supplying pressure-gas from said pressure-gas chamber to the lower end of said liquid delivery means; well-gas conveying means for conveying well-gas from the space in said well to the interior of said liquid delivery means at a point above the liquid level of said well; and a well-gas check valve for preventing a reverse flow through said well-gas conveying means. i 6. A gas-lift comprising: a liquid delivery means adapted to be extended into a well, the lower end extending below the liquid level of said well; a main valve near the lower end of said liquid delivery meansfor preventing liquid from flowing from said liquid delivery means into said well; pressure-gas supply means for supplying pressure-gas to the lower end of said liquid delivery means walls forming a well-gas conveying passage connected to said well and to the interior of said liquid delivery means; and check means for preventing a flow from the interior of said liquid delivery means into said well-gas conveying passage.

7. A gas-lift comprising: a liquid delivery means adapted to be extended into a well, the lower end extending below the liquid level of said well; a main valve near the lower end of said liquid delivery means for preventing liquid from flowing from said liquid delivery means into said well; pressure-gas supply means for supplying pressure-gas to the lower end of said liquid delivery means; walls forming a well-gas conveying passage connected to said well and to the interior of said liquid delivery means above the liquid level of said well; and check means for preventing a flow from the interior ofsaid liquid de livery means into said well-gas conveying passage.

8. A gas-lift comprising: a liquid delivery means adapted to be extended into a well, the lower end extending below the liquid level of said well; a main valve near the lower end of said liquid delivery means for preventing liquid fromflowing from said liquid delivery means into said well; pressure-gas supply means for supplying pressure-gas to the lower end of said liquid delivery means; walls forming a well-gas conveying passage around the lower end of said liquid delivery means and connected to said well and to the interior of said liquid delivery means; and check means for preventing a flow from the interior of said liquid delivery means into said wellgas conveying passage.

9. A gas-lift comprising: a liquid delivery means adapted to be extended into a well, the lower end extending below the liquid level of said well; a main valve near the lower end of said liquid delivery means for preventing liquid from flowing from said liquid delivery means into said well; pressure-gas sup ply means for supplying pressure-gas to the lower end of said liquid delivery means;

walls forming a well-gas conveying passage around the lower end of said liquid deliverj means and connected to said well and to the interior of said liquid delivery means above the liquid level of said well; and check means for preventing a flow from the interior of said liquid delivery means into said wellgas conveying passage.

In testimony whereoef, we have hereunto set our hands at Long Beach, California, this 8th day of A ril, 1927.

ILLIAM A. GAMMAOK. DONALD G. KNOX. 

